1. Field of the Invention
The present invention relates to an improvement in perpendicular magnetic recording/reproducing thin film heads of a single magnetic pole type which are used for electronic computers, magnetic tapes, video recording, etc. More particularly, it relates to a perpendicular magnetic recording/reproducing thin film head of a single magnetic pole type and having improved cross-talk and off-track properties of the thin film magnetic head by shaping a magnetic member for a return path filled with non-magnetic material and placed at a position opposing a magnetic recording medium after fabrication. The assembly is such that the width of the magnetic member for the return path, disposed in parallel with a main magnetic pole film, is substantially equal to the width of the main magnetic pole film. The magnetic member for the return path other than the parallel portion of the magnetic member is not in parallel with the main magnetic pole film.
2. Realted Art
Generally, a perpendicular magnetic recording/reproduction thin film head (hereinafter simply referred to as a magnetic thin film head) is suitable for higher density magnetic recording since the size of the magnetic circuit is small and a magnetic thin film of high permeability and high saturation magnetic flux density is used. Further, since it can be manufactured by a production process based on semiconductor technology, a highly accurate magnetic head can be produced at a reduced cost. It is therefore considered that such a thin film head will become a significant component in perpendicular magnetic heads.
The magnetic thin film head includes, for example, an inductive head used as a recording/reproducing head and a magnetoresistive effect head used as a reproducing head, or other similar magnetic component.
As shown in FIGS. 8a and 8b, which are explanatory views for the medium-opposing face and a vertical cross section of a transducer of a thin film head, and inductive head for a perpendicular magnetic recording/reproduction comprises, for example, a magnetic member 10, for example, made of soft ferrite, a main magnetic pole film 7 made of permalloy, senduct or Co-based amorphous material disposed with respect to the member 10 by a non-magnetic member 3 as a gap-layer, thin film conductor coils 4 and an insulation layer 5, a thick magnetic film 8, for preventing magnetic saturation of the main magnetic pole film 7 upon recording, and a protective film 9.
In the perpendicular thin film head of a construction opposed at the exposed laminated end face to a recording film, since a boundary 12, between the magnetic member 10 for the return path to a recording medium 30 and non-magnetic member 3 filled in a groove 2 of the magnetic member 10, is in parallel with the main magnetic pole film 7, the cross-talk property and the off-track property are not sufficient due to the unwanted reproduction in adjacent tracks at the boundary 12 other than the portion below the main magnetic pole film 7 and, accordingly, there has been a problem with increasing track density.
Additionally, in the conventional magnetic thin film head, since an edge-like portion of the magnetic member for the return path, that is, the boundary 12, is exposed in addition to the main magnetic pole film at the surface opposed to the recording medium, and magnetic flux leakage from the recovering medium are concentrated to the edged portion due to the contour effect of the exposed portion, there has been a problem of a resulting waveform distortion and deterioration in the recording density property due to the development of a side signal peak (the peak due to the contour effect) other than the main signal peak.